Truck elevator



M. L. ROBB TRUCK ELEVATOR Dec. 13, 1966 2 Sheets-$heet 1 Filed Sept. 22,1965 I/VVE'IVTOI? MORE/SON L. R0198 ATTORNEYS.

United States PatentO Filed Sept. 22, 1965, Ser. No. 489,204 4 Claims.(Cl. 1879) This invention relates to a truck elevator, and moreparticularly, to an elevator adapted to be mounted in the rear end of atruck to facilitate loading and unloading material.

from the floor of the body of the truck to ground level and vice versa.

A large number of truck elevators have been proposed heretofore. Thetruck elevator of the present invention is substantially simpler thanthose proposed heretofore, easier to install, is more inexpensive, andrequires less maintenance.

The truck elevator of the present invention is structurally interrelatedin a novel manner whereby a casing is reciprocally supported withrespect to a piston rod supported by the truck body. The length of thecasing or cylinder is slightly greater than the distance between theupper surface of the floor on the. truck body and the reference surfacesuch as the ground or the like. The elevator means is mounted forrotation about the longitudinal axis of the cylinder or casing. In oneembodiment of the present invention, the cylinder is mounted forrotation with respect to the piston rod. In another embodiment of thepresent invention, the piston rod is supported for rotation about itslongitudinal axis.

It is an object of the present invention to provide a novel truckelevator.

It is another object of the present invention to provide a truckelevator which is simple, reliable, inexpensive, and comprised of aminimum number of components.

It is another object of the present invention to provide a truckelevator having a cylinder mounted for rotation about its longitudinalaxis.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there are shown in thedrawings forms which are presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIGURE 1 is a rear elevation view of a truck incorporating the elevatormeans of the present invention.

FIGURE 2 is a transverse sectional view taken along line 2-2 in Figure1.

FIGURE 3 is a side elevation view of the truck in FIG- URE 1 partlybroken away to illustrate the elevator means of the present invention.

FIGURE 4 is a sectional view on an enlarged scale taken along the line4-4 in FIGURE 2.

FIGURE 5 is a sectional view on an enlarged scale similar to FIGURE 4but illustrating another embodiment of the present invention.

Referring to the drawing in detail, wherein like numerals indicate likeelements, there is shown in FIGURE 1 a portion of a truck designatedgenerally as 10.

The truck includes a body designated generally as 16 mounted on wheels12 which in turn are supported by a reference surface 14 such as theground or the like. The truck body 16 includes floor 18, side walls 20and 22 and a top wall 24. The floor 18 has a rear face designated as 26.

The elevator means of the present invention is designated generally as28. The elevator means 28 is structurallv interrelated in a novel mannerso that it occupies a minimum amount of space while at the same timebeing simple, reliable and inexpensive to construct. The elevator means28 may be supplied with new trucks or added to existing trucks.

The elevator means 28 includes an upright stationary piston rod 32having a mounting bracket 34 at its upper end and a mounting bracket 36at its lower end. The brackets 34 and 36 are releasably secured to thetop wall 24 and floor 18 respectively adjacent one of the side walls 20and the face 26. Thus, see FIGURE 2.

A cylinder 38 having a length slightly greater than the distance betweenthe upper surface of floor 18 and the surface 14 is reciprocallysupported by the piston rod 32 for reciprocating along its longitudinalaxis. Cylinder 38 is concentric with piston rod 32 and provided at itsupper end with a bearing seal 40. A comparable bearing seal 42 isprovided at the lower end of cylinder 38. A piston 44 is fixedly securedto the piston rod 32 intermediate the ends of rod 32.

The piston rod 32 is provided with a motive fluid passage 46communicating with the cylinder 38 below piston 44. A comparable motivefluid passage 48 is provided in the piston rod 32 and communicates withthe chamber in cylinder 38 above piston 44. The passages 46 and 48 areadapted to be in communication with each other by way of a conduit 50.The conduit 50 communicates with the passages 46 and 48 at the ends ofthe piston rod 32 within or adjacent to the mounting brackets 34 and 36.

In FIGURE 1, the cylinder 38 is adjacent its uppermost position. InFIGURE 3, the cylinder 38 is adjacent its lowermost position. In orderto move the cylinder 38 between its uppermost and lowermost positions,the conduit 50 is provided with a pump 52 which may be a motor operatedpump. As illustrated, pump 52 is a manually operable pump having amanually actuable handle 54. Pump 52 may be of the hydraulic orpneumatic type commercially available and utilized in connection withbumper jacks. Handle 54 may be removed or disconnected by unthreadingthe same.

In order that the cylinder 38 may support a load designated generally as30 and move the same from the phantom position illustrated in FIGURE 1to a position wherein it is supported by the ground 14, a load supportmeans is fixedly secured to the outer periphery of cylinder 38. The loadsupport means may include in its simplest form a channel member 56having its free ends welded or otherwise fixedly secured to theperiphery of cylinder 38. A mounting plate 58 is secured to the channel56 adjacent its lowermost end in any convenient manner such as bywelding. A pair of support plates 60 and 62 are fixedly secured to themounting plate 58 in any convenient manner such as by welding. It willbe noted that the support plates 60 and 62 are spaced from one anotherand have a horizontally disposed portion and a vertically disposedportion. The horizontally disposed portions of the plates 60 and 62 areadapted to be in the same horizontal plane resting on the upper surfaceof floor 18. The vertically disposed portions of the plates 60 and 62are connected to the mounting plate 58. As shown more clearly in FIGURES2 and 3, the radius of cylinder 38 is sufficiently large so that thechannel member 56 may reciprocate toward and away from the ground 14without contacting the upper surface of floor 18. It will be noted thatthe horizontal portion of the plates 60 and 62 is longer than thevertical portion.

The operation of the elevator means 28 in connection with transferring aload from the floor 18 to the ground 14 is as follows:

The cylinder 38 will be rotated from its storage position to theposition illustrated in solid lines in FIG- URE 2. Such rotation may bemanually accomplished by pulling on the plate 62. Thereafter, the load30 may be positioned so as to be supported by the plates 60 and 62. Thehandle 54 is then actuated to pump some of the fluid above piston 44through passage 46, conduit 50, passage 48 into the casing 38 abovepiston 44. Such pumping action need only be sufficient to raise the load3 30 and plates 60 and 62 to an elevation several inches above the floor18.

The elevator means 28 together with the load 30 is then manually rotated90 to the phantom position in FIGURE 2. Thereafter, the handle 54 isactuated to permit the motive fluid to bleed from the chamber withincylinder 38 above piston 44 to the chamber within the cylinder belowpiston 44 by way of said passages and conduit 50. No pumping action isrequired due to the fact thatthe weight of the load will force themotive fluid through conduit 50. The operator will of course controlhandle 54 so as to cease permitting bleeding of the motive fluid whenthe plates 60 and 62 contact the ground 14.

As soon as the load 30 is transferred to the solid line position inFIGURE 1 wherein it is supoprted by a reference surface 14', theoperator may then reverse the above sequence wherein the handle 54 willbe actuated to pump the fluid from within the casing 30 and below piston44 to a position above the piston 44 within the casing 38. This willraise the support plates 60 and 62 until they can clear the uppersurface of the floor 18. Thereafter, the process is repeated.

In FIGURE 5, there is partially illustrated another embodiment of thepresent invention wherein the elevator means is designated as 28. Theelevator means 28 is identical with the elevator 28 except as will bemade clear hereinafter. Hence, corresponding elements are provided withcorresponding primed numerals.

In the elevator means 28', the piston rod 32' is mounted for rotationwith the casing 38. Thus, there is no rela tive rotative movementbetween cylinder 38' and the piston disposed therewithin and secured tothe piston rod 32'.

The mounting brackets 34' and 36' for the piston rod 32' are identical.Hence, only the mounting bracket 34 removably secured to the top wall 24will be described in detail. The bracket 34' includes a cup-shapedhousing through which the piston rod 32' extends and terminates in aremovable head 68. The head 68 is provided with a semi-spherical bearing66 integral with a plate threadedly coupled to the cup-shaped housing.Roller bearings may be provided beneath the head 68 and above thejuxtaposed portion of the cup-shaped housing. In view of the ability ofthe piston rod 32 to rotate through an arc of approximately 180, theconduit 50' is flexible and of suflicient length so as to permit suchrotation. The elevator means 28' is otherwise identical with thatdescribed above and therefore need not be described in detail. In viewof the above description, a more detailed description of the elevatormeans 28 is not deemed necessary.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim: I

1. A truck elevator comprising a cylinder surrounding a piston rod, saidpiston rod extending through and beyond the ends of said cylinder, apiston fixed to said rod within said cylinder, whereby said cylinder maybe reciprocated along said rod, said piston defining end walls of anupper and lower chamber in said cylinder, conduit means connected to theupper chamber in said cylinder, conduit means connected to the lowerchamber in said cylinder, means associated with each of said conduitmeans for controlling the flow of hydraulic fiuid through said conduitmeans, a first passage extending through said rod and opening into saidupper chamber on one side of said piston, a second passage extendingthrough said rod and opening into said lower chamber on the other sideof said piston, said passages being in communication with said conduitmeans, mounting brackets securing the ends of said rod in an uprightdisposition, said cylinder being mounted for rotation about itslongitudinal axis, load support means secured to said cylinder formovement with said cylinder, and said load support means including atleast one support plate extending in a direction substantiallyperpendicular to the longitudinal axis of said cylinder.

2. A truck elevator means in accordance with claim 1 including bearingmeans at the ends of said piston rod rotatively supporting said rod formovement about its longitudinal axis, and said load support meansincluding at least one support plate extending in a direction substantially perpendicular to the longitudinal axis of said cylinder.

3. Elevator means in accordance with claim 1 wherein said means forcontrolling flow through said conduit means includes a manually operablepump.

4. Elevator means in accordance with claim 1 wherein said load supportmeans includes a channel member extending parallel to said cylinder andsecured to the outer periphery of said cylinder, said channel memberbeing longer than said cylinder, and at least one support plate fixedlysecured to an end portion of said channel member remote from saidcylinder, said support plate extending in a direction substantiallyperpendicular to the longitudinal axis of said cylinder.

References Cited by the Examiner UNITED STATES PATENTS 2,540,569 2/1951Crise. 2,930,499 3/1960 Landen 214- 3,134,231 5/1964 McCreery' 92-1l73,174,634 3/1965 Peck 1879 FOREIGN PATENTS 136,275 11/ 1902 Germany.

1,054,018 3/ 1959 Germany.

EVON C. BLUNK, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.

Notice of Adverse Decision in Interference In Interference No. 96,226involving Patent No. 3,291,261, M. L. Robb, TRUCK ELEVATOR, finaljudgment adverse to the patentee was rendered Apr. 20, 1970, as to claim1.

[Oyfioial Gazette September 8, 1970.]

1. A TRUCK ELEVATOR COMPRISING A CYLINDER SURROUNDING A PISTON ROD, SAIDPISTON ROD EXTENDING THROUGH AND BEYOND THE ENDS OF SAID CYLINDER, APISTON FIXED TO SAID ROD WITHIN SAID CYLINDER, WHEREBY SAID CYLINDER MAYBE RECIPROCATED ALONG SAID ROD, SAID PISTON DEFINING END WALLS OF ANUPPER AND LOWR CHAMBER IN SAID CYLINDER, CONDUIT MEANS CONNECTED TO THEUPPER CHAMBER IN SAID CYLINDER, CONDUIT MEANS CONNECTED TO THE LOWERCHAMBER IN SAID CYLINDER, MEANS ASSOCIATED WITH EACH OF SAID CONDUITMEANS FOR CONTROLLING THE FLOW FO HYDRAULIC FLUID THROUGH SAID CONDUITMEANS, A FIRST PASSAGE EXTENDING THROUGH SAID ROD AND OPENING INTO SAIDUPPER CHAMBER ON ONE SIDE OF SAID PISTON, A SECOND PASSAGE EXTENDINGTHROUGH SAID ROD AND OPENING INTO SAID LOWR CHAMBER ON THE OTHER SIDE OFSAID PISTON, SAID PASSAGES BEING IN COMMUNICATION WITH SAID CONDUITMEANS, MOUNTING BRACKETS SECURING THE ENDS OF SAID ROD IN AN UPRIGHTDISPOSITION, SAID CYLINDER BEING MOUNTED FOR ROTATION ABOUT ITSLONGITUDINAL AXIS, LOAD SUPPORT MEANS SECURED TO SAID CYLINDER FORMOVEMENT WITH SAID CYLINDER, AND SAID LOAD SUPPORT MEANS INCLUDING ATLEAST ONE SUPPORT PLATE EXTENDING IN A DIRECTION SUBSTANTIALLYPERPENDICULAR TO THE LONGITUDINAL AXIS OF SAID CYLINDER.